1. Field of the Invention
The present invention relates a method and apparatus for acoustic noise cancellation in medical devices and, more particularly, to respiratory treatment devices with acoustic noise cancellation.
2. Background Information
In the field of respiratory treatment devices, minimizing sound emission of the device is of significant concern. This is because respiratory treatment devices, such as a continuous positive airway pressure (CPAP) device, are commonly utilized by patients during periods of sleep, for example to treat sleep apnea. Any noise can serve to disrupt the patients sleep and should be minimized. In addressing this issue, existing respiratory devices have utilized sound insulating materials, e.g. foam, in the housing construction. The insulation or foams of the prior art are reliable methods of reducing airborne noise. However, achieving a sufficient noise reduction using sound insulating materials becomes difficult with smaller product profiles. In other words, as the respiratory treatment products are becoming smaller, the thickness of the insulation is decreased, and the effectiveness of the foam is reduced.